How to purchase itunes gift card?

Is there any store nearby to my place

Please check in your region, we don't know where you live.

Where to buy a physical Apple Gift Card or App Store & iTunes gift card: at an Apple Store or an Apple Authorized Reseller in your region.

See -> How to redeem your Apple Gift Card or App Store & iTunes gift card

How to redeem your Apple Gift Card or App Store & iTunes Gift Card – Apple Support (UK) 

or it can be done from online?

If you have a valid payment method on file, instead of buying or order an App Store & iTunes gift card, you can Add money to your Apple Account balance anytime, no gift card needed, see -> Apple Gift Card - Apple (UK)

See also:  If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card

If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card - Apple Support

Beware of -> About Gift Card Scams -> About Gift Card Scams - Official Apple Support